Method and apparatus for preparing composite assembly



March 7, 1961 E. R. SMITH ETAL 2,974,077

METHOD AND APPARATUS EoR PREPAPTNG COMPOSITE ASSEMBLY Filed June 21, 1957 3 Sheets-Sheet 1 WM Ii March 7, 1961 E. R. SMITH TAL 2,974,077

METHOD AND APPARATUS FOR PREPARING COMPOSITE ASSEMBLY Filed June 2l, 1957 5 Sheets-Sheet 2 March 7, 1961 E. R. SMITH ETA'. 2,974,077

METHOD AND APPARATUS FOR PREPARING COMPOSITE ASSEMBLY Filed June 21, 195'? 3 She'ets-Sheet 3 Unite States .rg-r' METHOD AND APPARATUS FOR PREPARING COMPOSITE ASSEMBLY Earl R. Smith, Northridge, Calif., and Harry L. Ziegler,

Delmont, Pa., assignors to Pittsburgh Plate Glass Company, Allegheny County, Pa., a corporation of Pennsylvania l Filed June 21, 1957, Ser. No. 667,262

: Claims. (Cl. 154-25) This invention relates to a method and an apparatus for preparing a composite assembly comprising two matched curved glass sheets and a thermoplastic interlayer.

In the preparation of a curved laminate havingtwo matched curved glass sheets and `a thermoplastic inter-I layer bonded to the gl-ass sheets, such as a'curved windshield, a pair of matched curved glass sheets is prepared. This is done conventionally by bending the two glass sheets together to provide the matching relationship. Of course, to place the thermoplastic sheet, such as a plasticized polyvinyl butyral sheet, between the pair of matched curved glass sheets it is necessary to separate the pair of glass sheets. This has been done by placing the pair of glass sheets on a support with the outer sheet of the pair resting on the support so that the ends of the pair pointed upwardly. The inside glass sheet was lifted from the outer glass sheet and thev thermoplastic sheet was placed on the outer sheet. The inner glass sheet was placed on the thermoplastic sheet to form the composite assembly that was subjected to a process for bonding the interlayer to the two glass sheets.

. edge of the top glass sheet serving as a guide.

ICC

of these later designs of windshields. p For example, it

has become difficult to properly position the thermo-t. plastic sheet onto the curved glass sheet having its ends. extending sharply upwardly because of the sharp bends in the sections intermediate the ends and the central section. The operator when placing the thermoplastic sheet on the outer glass sheet found it to be diicult to properly position the thermoplastic sheet to cover the entire area of the outer glass sheet. The thermoplastic sheet at its ends would have a tendency to fall away from the end sections of the glass sheet thereby providing wrinkles or folds in the former. Unless eliminated by a smoothing action with the hands immediately before placing the inner glass sheet on the thermoplastic sheet, folds of plastic would remain between the glass sheets. The assembly after lamination would have an unsatisfactory appearance.

The thickened areas of plastic at the folds would prevent the two glass sheets from being returned almost to their original matchingrelationship. Furthermore, the thickened areas of thermoplastic material would prevent bonding of the plastic to the glass sheets in other areas; Another disadvantage of this method is that the sliding of the plastic sheet at its ends would expose areas of the outer glass sheet that would be contacted by the inner glass sheet being placed on the thermoplastic sheet and the contact wou-ld cause damage such as scratching.

Before laminating the composite assembly, it is necessary to trim excess thermoplastic sheet material by moving a razor blade around the sandwich with the top of the The matched curved glass sheets were supported so that-the assembly was concave in elevation. This made it diticult to trim the edges from the plastic interlayer because of the diiculty in obtaining access :for the razor into the sharply bent portions.

To carry out this method on a continuous basis, pairs I of the curved glass sheets were separated in sequence. For each, the outer glass sheet was supported-with its ends pointing upwardly. The support was provided on the undersurface of the glass sheet midway between its ends, i.e., along a center line that was transverse to the length of the curved glass sheet. The supported outer curved glass sheet was passed through an assembly zone in which the thermoplastic sheet was placed on this glass sheet. The other glass sheet was placed on the thermoplastic sheet to form the composite assembly. The movement of the outer glass sheet through the assemblyV zone was provided by supporting it one a conveyor belt and the glass sheet was positioned on the belt so that its longitudinal axis was parallel to the path of movement provided by the conveyor belt. separated inner curved glass sheet was placed on the conveyor belt approximately alongside the outer glass sheet so that the former was supported in a tilted position with portions of the edges of the end sections and the central section along one side contacting the conveyor belt. After the thermoplastic sheet was placed on the outer glass sheet, the inner glass sheet was lifted from the conveyor belt and was rotated about its longitudinal axis unitl the ends of the glass sheet pointed upwardly. The inner glass sheet was lowered onto the thermoplastic interlayer.

Originally the curvature of the windshields was cylindrical. The automobile windshields became larger. Windshields were designed with a cylindrical central section and with sections intermediate the ends and the central section that had smaller radii of curvature than the central section.

The foregoing method of assembling the interlayer between the two sheets of glass has been found -to have The diliiculties and disadvantages of the foregoing method for the preparation of a composite assembly are encountered when the curved glass sheets are sharply curved in areas between the center section and the end section and the end sections are twisted about the longitudinal axis of the sheets. In these glass sheets the end sections may be considered to be conical `and the central section is cylindrical -in shape.

The windshields have become so massive that support of the outer glass sheet merely along a transverse line at its center during the assembly operation resulted in a In this continuous operation the numerous disadvantages when used for the manufacture slight change in the curvature of the glass sheet. As a result of the sagging, the end sections were farther apart than desired. The final lwindshields were ditlicult to mount in the supporting frame in an automobile.

It is an object of this invention to provide a method and an apparatus for assembling a vcurved composite assembly in which the thermoplastic sheet canA be easily and properly positioned on one of the glass sheets without the creation by sliding of folds in the thermoplastic sheet.

It is another object of the present invention to provide a method and apparatus for preparing a composite assembly so that the glass sheets are supported in a manner to minimize a change in curvature of the glass sheets during the assembly operation.

A further object of this invention is to provide a con-v tinuous method and an apparatus for preparing a comlposite assembly so that without rotation of the composite assembly about its longitudinal axis the excess thermoplastic material can be trimmed with the minimum amount of fragmentation of the glass sheet serving as a guide for the trimming tool and with the minimum amount of wear of the trimming tool. j Still another object of the present invention is to pro,- vide an apparatus with which two operators on opposite Y '2,974,1)77 PatentedMar. j

on one of the glass sheets and can cooperate with eachother to lift the second glass sheet onto the thermoplastic sheet.

Another object of the invention is to provide an apparatus for use in the preparation of a composite assembly in which the operators preparing the assembly on the apparatus can readily detect any defects in the glass sheets and any defects or wrinkles in the entire area of the thermoplastic sheet.

These and other objects of the present invention will be apparent to one skilled in the art from the description of the method and apparatus, taken in conjunction with the drawings, that follows.

In accordance with the method of this invention a curved glass sheet is supported with its convex surface facing upwardly, i.e., with its ends pointing downwardly. In the preferred embodiment of this step the glass sheet is supported at transversely spaced areas between the center of the sheet and its ends rather than being supported along a transverse line in the center of the sheet. This minimizes the possibility of a change in the curvature of the glass sheet during the assembly process. A thermoplastic sheet is placed or draped across the top convex surface of the supported curved glass sheet and the matching curved glass sheet is placed on the upper major surface of the thermoplastic sheet to produce the composite assembly. After trimming of excess thermoplastic sheeting, the assembly is ready for laminating to bond the thermoplastic sheet to the two glass sheets.

Because the two matched glass sheets are conventionally prepared by bending them together on a mold, the method of this invention usually includes the step of separating the two matched curved glass sheets before placing one of the glass sheets with its convex surface facing upwardly to place the thermoplastic sheet on it.

In the method it is preferred that thermoplastic sheet be placed on the top convex surface of one of the two glass sheets as they are being moved in a path. Of course, the other separated glass sheet, that is moved, is preferably supported in a similar manner to minimize any changing in curvature until it is placed on the thermoplastic sheet.

During the assembly steps of the method it is preferable that the two glass sheets move in ya horizontal direction, although the method can be carried out while the general direction of the glass sheets is vertical or inclined so long as the one glass sheet on which the thermoplastic sheet is placed is maintained in a supported position with its ends pointing downwardly.

The apparatus of this invention is illustrated below by a preferred embodiment that is shown in the drawings in which:

Fig. 1A is a side elevation of part of the apparatus with part of the apparatus removed in the right-hand portion;

Fig. 1B is a side elevation of the other part of the apparatus;

Fig. 2 is a fragmentary plan view of the central portion of the apparatus;

Fig. 3 is a fragmentary plan view of the portion of the apparatus shown in Fig. 1B;

Fig. 4 is a fragmentary front elevation of the apparatus as seen from the left end of Fig. lA with one of the supporting carriages removed; and

Fig. 5 is an elevation of the straddling table for supporting sheets of thermoplastic material above the conveyor portion of the apparatus shown schematically.

The apparatus has a supporting structure generally indicated at mounted on a oor F. As seen in Fig. lA the floor F has a well 11 in which is mounted a motor 12. A sprocket 13 is keyed on the shaft 14 of motor 12. There is a well 15 in floor F at the other end of the apparatus as seen in Fig. 1B. The well 11 is covered with a slotted plate 18.

The supporting structure 10 has a spaced pair of rows of upright supports 2G. The upright support 26 of one row opposite an upright support 20 of the other row is connected to the latter at the top by channel iron 21 and at the bottom by angle iron 22. In each row the upright support member 20 is connected to the adjacent upright member 20 by bracing members 23.

Upright angle irons 24 of supporting structure 10 are secured to channel members 21 between the ends of the latter. A pair of spaced bottom support rails 26 is se cured to upright angle irons 24. At one end, as seen in Fig. 1B, the bottom rails are inclined downwardly and at the very end of the inclined portions the rails 26 are ared downwardly. Guide rails 28 are secured to the supporting structure 10 above the inclined portion of rails 26 and each is flared upwardly at one end. A pair of top support rails 36 is secured to upright angle irons 24. At one end (Fig. 1B) top support rails 30 are inclined upwardly. A pair of top guide rails 32 is secured to the supporting structure 10 above the inclined portion of top support rails '30 and each is inclined upwardly.

A pair of roller chains 34 is supported by bottom and top support rails 26 and 30 and chains 34 engage sprockets 35 xed on a shaft 36 rotatably mounted at one end of supporting structure 10 by pillow blocks 38. A sprocket is xed on shaft 36 by a key 42. A chain 44 engages sprockets 13 and 40. The motor 12 rotates shaft 36 by means of sprockets 13 and 40 and chain 44. The chains 34 at the other end of supporting structure 1G engage a pair of idler sprockets 46 and a pair of idler sprockets 43. The idler sprockets 46 are keyed on a shaft 50 rotatably mounted by bearings 52 mounted On inclined channel v irons 54 of supporting structure 10. The top portions of channel irons 54 are secured to the top portions of a pair of channel irons 56 of the supporting structure lll which are joined at an intermediate point by angle iron 58. The channel irons 56 also support the inclined portions of support rails 26 and 30 and guide rails 2B and 32 by means of brackets 60 and 62, angle irons 64 and 66 and plates 68.

The idler sprockets 43 are fixed on a shaft 70 rotatably mounted by bearings 72 adjustably mounted on channel irons 54 by means of guide members '74 secured to channel irons 54, threaded rods 76 rotatably secured to bearings 72, and nuts 78 to brackets 80 secured to channel irons 54. The shaft 70 supported by bearings 72 passes through channel members 54 at slots 81.

The rollers 82 of chains 34 rotate on and are supported by rails 26 and 30. The motor 12 drives chains 34 as described above so that the chains 34 when they are on rails 30 move from right to left in Figs. lA and lB. The chains 34, therefore, move from left to right on rails 26 at the same time. The top run of chains 34 is horizontal along the major distance of the apparatus. The bottom run of chains 34 is similar to the top run in this respect. At the one end of the apparatus, chains 34 by engaging driving sprockets 40 are simply and rapidly reversed in their direction from movement to the left to movement to the right. At the other end of the apparatus, the idler sprockets 46 and idler sprockets 48 are positioned to provide an inclined rectilinear run of chains 34.

Supporting brackets S4 are secured to chains 34 at various points along these chains. Carriages generally indicated at 86 are secured to brackets 84. Each of carriages 86 has a pair of angle irons 38 welded at their ends to plates 90. The angle irons 83 of carriage S6 `are secured to supporting brackets 84 fastened to chains 34.

The flange 92 of both angle irons S8 of each carriage 86 has elongated slots 94 and a central elongated slot 9:5 between slots 94. Each of a pair of slotted plates 9S and a pair of slotted plates 99 is secured to both angle irons 88 on flanges 92 by meansjof athead screws 100 and nuts 102. The slots in plates 98 and 99 are tapered at the top to receive the tapered heads of screws 100, so that 1agradar" 5 the top of each screw 100 is iiush 'with the top of plates 98 and 99. The plates 98 and 99 are thus secured to angle irons 88 adjacent both ends of the latter angle irons 88. Similarly, a plate 103 is secured to the central portion of angle irons 88.

Arms 104 having elongated slots 106 are secured to plates 98 and plate 103. Arms 108 having elongated slots 110 are secured to plates 99. The arms 104 and 108 are secured to plates 98, 99 and 103 by screws 100. Of course, the screws 100 that pass through slots 106 or 110 and plates 98, '99 or y103, whether or not through flanges 92, are not required to be flat head screws, but such are preferred. In this case, the slots 106 and 110 are tapered at the top of their side wal-ls.

Resilient pads 120, such as rubber pads, are secured to arms 108 at their free ends, that is, at their forwardly extending ends. The top surface of each of pads 120 is inclined downwardly toward angle irons 88. This construction provides for substantially edge contact of the curved glass sheets G thereby minimizing the amount of undesirable contact with the surface of the outer glass sheet G that will be bonded to the thermoplastic sheet. The pad 120 contacts the glass sheet G at its edge as the latter is moved up the inclined path of travel shown at the far right-hand side of Fig. 1B and is moved along a horizontal path before removal to place it on the thermoplastic sheet that has been placed on the other glass sheet.

Each of the arms 104 includes at its free end, i.e., the end rearward of the angle irons 88, an upstanding flange 121'. Resilient pads 122 are secured to arms 104 and their flanges 121. The pads 122, which may be constructed of rubber, preferably extend upwardly beyond flanges 121. The upper extension is narrower in one dimension than the base of pad 122. The upper extended portion has a notch 123 in the surface that opposes pads 120 on arms 108.

The arms 184 mounted to plates 98 and 103 and arms 108 mounted to plates 99 can be moved or adjusted because of the foregoing construction so that the distance between the pads 120 and 122 of arms 108 and 104, respectively, as well as the spacing between pads 120 and between pads 122 can be varied to provide the -desired four areas of contact support for glass sheets G or curved assemblies A.

The arm 104 on plate 103 is not utilized to support the large windshields being made. It is on carriage 86 so that the equipment can be utilized for the support of rela,- tively small curved glass sheets. In this case, of course, arms 108 can be moved toward each other to provide support and one of the other arms 108 can be moved to provide another support.

Above the right-hand end of the horizontal portion of the conveyor, a table 130 straddles the apparatus. The table 130 supports piles of sheets of Vinal S, i.e., plastieized polyvinyl butyral, that are used as the interlayer for the assembly. Two operators, one on each side of the conveyor, can reach a sheet S on table 130. In the embodiment shown, the table has two tiers for supporting two or more sets of plastic sheets S cut to pattern. With this arrangement, sheets S can be withdrawn from either pile depending upon the matched pair of glass sheets G being moved on carriages 86. Often at least two patterns of curved assemblies are prepared on the assembly apparatus. The pair of matched sheets G of one pattern may follow alternately a pair of matched sheets G of another pattern. In some cases several pairs of one pattern are assembled before several pairs of another are assembled. The legs of table 130 have wheels 132 so that the position of table 130 along the horizontal portion of the conveyor can be readily adjusted.

Before placing the thermoplastic sheet S on the inner glass sheet G as it is moved on rcarriage 86 in a horif zontal path by the conveyor, the sheet S is lifted from yarms 104 and 108 to move it out of notches 123 and then sheet G is placed on pads and 122 as indicated for? composite assembly A in the left-hand portion of Fig. 1A;` that is, with the inner glass sheet G resting on the tops of Vpads 120 and 122 and preferably overhanging these pads.

Because carriages 86 of the apparatus support the glass sheets G or the final composite assembly A, with the ends pointing downwardly as they are being moved by the apparatus, the apparatus has been provided with banks of lights mounted to the supporting structure 10 between the rows of upright supports 20 and below and between channel irons 21. The lights 140 are supported to provide a horizontal bank of lights 140 below the central portions of carriages 86 and banks of lights 140 on each side of and inclined downwardly away from the central bank. The arrangement of the three banks of lights 140 can be seen in Fig. 5. The three banks of lights 140, each in longitudinal rows below carriages 86, are also shown in Fig. 3. l'

At the loading end of the apparatus, i.e., at the extrme right end of Fig. 1B, an operator loads a pair of matched curved glass sheets G on one carriage 86, as indicated for the leading glass sheet G on the carriage 86 referred to below as the leading carriage at the top of the inclined portion. Of course, during loading of the pair of glass sheets G on this carriage 86, it is in the position indicated by the next carriage referred to below as the trailing carriage 86. The arms 104 and 108 of the leading and trailing carriages 86 are preferably adjusted as shown in the drawings so that the glass sheet G on the leading carriage when resting in notches 123 overhangs pads 120 before sheet G is repositioned for assembly with the plastic sheet S and the other sheet G. When repositioned, the leading or inner sheet G rests on the top of pads 120 and 122 and preferably overhangs to permit excess plastic sheet trimming. For the trailing carriage 86, arms 104 and 188 are preferably positioned farther apart than is the case for the leading carriage 86 so that the edge areas only of the trailing or outer glass sheet G rest on the inclined surfaces of pads 120 and the bottom inclined surfaces of notches 123 of pads 122.

While the chains 34 raise the carriage 86 a short distance, the operator by conventional lifting means, such as a small vacuum cup, tilts the outer glass sheet G away from the inner glass sheet G, lifts the former out of notches 123 and removes it from leading carriage 86. The operator holds the outer glass sheet G until the next or trailing carriage 86 larrives at the loading point.V The operator then places it on the trailing carriage 86 in the same manner, i.e., with the one edge of the glass sheet G resting in notches 123 and the opposite edge resting on pads 120 with the edge of sheet G preferably contacting the inclined top surface.

As these two carriages 86 are moved along the hori-y first glass sheet G and no longer in notches 123 as described above and preferably overhangs pads 120. As soon as the second glass sheet G on itscarriage 86 has passed beyond table 130, it is grasped at its ends by the two operators, lifted, moved forwardly, andplaced on the thermoplastic sheet S on the rst curved glass sheetr` G. The resultant composite assembly A is moved along;

on the first carriage 86 until it reaches a position near the left end of the horizontal pathon rails .30. The

composite assembly A, before it has reached this point,

can be trimmed with a razor blade to remove excess plastic. The top portion of the edge of the top or outer sheet G is used as a guide for sliding the razor blade around the assembly A. After removal of the composite assembly A from the apparatus of the invention, it is subjected to any of the processes developed for laminating curved composite assemblies to bond the thermoplastic interlayer to the glass sheets.

The foregoing description of the method and the apparatus has been presented for purpose of illustration only. Many modifications will be apparent to one skilled in the art. rlhe invention is limited only by the claims which follow.

We claim:

l. A method for the preparation of a curved composite assembly which comprises supporting a curved glass sheet with its convex surface facing upwardly, placing a thermoplastic sheet on the supported sheet, and placing a matching curved glass sheet on the upper major surface of the thermoplastic sheet to form the composite assembly.

2. A method for the preparation of a curved composite assembly which comprises placing a curved glass sheet with its convex surface facing upwardly, supporting the sheet only at transversely spaced areas between the center of the sheet and its ends, placing a thermoplastic sheet on the supported sheet, and placing a matching curved glass sheet on the upper major surface of the thermoplastic sheet to form the composite assembly.

3. A method for the preparation of a curved composite assembly which comprises separating two matched curved glass sheets, placing one of the glass sheets with its convex surface facing upwardly, supporting the separated glass sheets, moving the glass sheets in a path, placing a thermoplastic sheet on the moving glass sheet placed with its convex surface facing upwardly, and placing the other moving glass sheet on the upper major surface of the thermoplastic sheet to form the composite assembly.

4. A method for the preparation of a curved cornposite assembly which comprises separating two matched curved glass sheets, placing the separated glass sheets each with its convex surface facing upwardly, supporting the glass sheets only at transversely spaced areas between the center of each sheet and its ends, moving the supported glass sheets in a path, placing a thermoplastic sheet on the moving supported glass sheet having the convex surface originally abutted by the concave surface of the other glass sheet, and placing the other glass sheet on the upper major surface of the moving assembly of the thermoplastic sheet and the glass sheet to form the composite assembly.

5. The method of claim 4 wherein the path of movement of one of the glass sheets is horizontal during the placing of the thermoplastic sheet on said glass sheet, and the placing of the other matching glass sheet on the upper major surface of the thermoplastic sheet.

6. A method for the preparation of a curved composite assembly which comprises separating two matched curved glass sheets, placing the separated glass sheets each with its ends pointing downwardly, supporting the glass sheets only at transversely spaced areas between the center of each sheet and its ends, moving the supported glass sheets in a horizontal path normal to the radii of curvature of the glass sheets, placing a thermoplastic sheet on one of the moving supported glass sheets, and placing the other glass sheet on the upper major surface of the thermoplastic sheet to form the composite assembly being moved with its ends pointing downwardly.

7. A method for the preparation of a curved composite assembly which comprises separating two matched curved glass sheets, placing the separated glass sheets each with its ends pointing downwardly, supporting the glass sheets only at transversely spaced areas between the center of each sheet and its ends, moving the supported glass sheets in a horizontal path normal to the radii of curvature of the glass sheet, placing a thermoplastic sheet on one of the moving supported glass sheets, placing the other glass sheet on the upper major surface of the thermoplastic sheet to form the composite assembly, and moving a trimming tool in contact with the top portion of the edge of the `top glass sheet around the composite assembly being moved with its ends pointing downwardly to remove the thermoplastic sheet extending beyond the glass sheets.

8. An apparatus for the preparation of a curved composite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises sets of means for supporting a curved glass sheet with its ends pointing downwardly, each set being constructed and arranged to support one of said glass sheets only by contact of the set of support means with the lower major surface of the glass sheet at areas transversely spaced apart between the center of the glass sheet and its ends by transverse spacing and longitudinally spacing between the support means of each sheet, and means for conveying the sets of support means in a cyclic path, said conveyor means being constructed and arranged to provide said sets of support means in spaced relationship and with said support means of each set extending upwardly with an upper resilient portion for each support means during a top portion of said path to provide said contact of the glass sheet by the set of support means.

9. The apparatus of claim 8 wherein the conveying means is constructed and arranged to move the support means extending upwardly in a horizontal direction during said top portion of said cyclic path.

10. An apparatus for the preparation of a curved cornposite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises sets of support means and means for conveying said sets of support means in a cyclic path including a horizontal top portion in which the sets of support means extend upwardly in spaced relationship and an inclined portion of rectilinear travel, each of said set of support means being constructed and arranged to support in said horizontal portion of movement a curved glass sheet with its ends pointing downwardly by contact of the set of support means with the lower major surface of the glass sheet only at areas transversely spaced apart between the center of the glass sheet and its ends and in which each of the support means has an upper resilient portion.

l1. An apparatus for the preparation of a curved composite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises sets of first and second pairs of support means and means for conveying said sets of support means in a cyclic path including a horizontal top portion, said rst and second pairs of each set of support means each being spaced apart in one direction and said pairs being spaced apart in another direction and extending away from each other to provide during movement in the horizontal top portion of the path for support of a curved glass sheet with its ends pointing downwardly only by contact of the set of first pairand second pair of support means with the lower major surface of the glass sheet at areas transversely spaced apart between the center of the glass sheet and its ends and each of said support means having an upper resilient portion for contact with said lower surface of the glass sheet.

12. An apparatus for the preparation of a curved composite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises sets of first and second pairs of support means and means for conveying said sets of support means in a cyclic path including a horizontal top portion and an inclined portion, said first and second pairs of each set of support means each being spaced apart to move the tirst pair ahead of the second pair, said pairs being spaced apart in a direction traversing the path of movement provided by said conveyor means, each of said sets of support means during said horizontal top path of movement being constructed and arranged to support a curved glass sheet with its ends pointing downwardly only at areas transversely spaced apart between the center of the glass sheet and its ends by contact of the set of support means with the lower major surface of the glass sheet, each of said support means having an upper resilient portion to contact said lower surface of the glass sheet, and said second pair of support means of each set having a notched surface portion opposing the rst pair of that set whereby the curved glass sheet is supported by the rst pair of support means and is supported and raised by the second pair of the support means in the inclined portion of the cyclic path of movement of the sets of the support means.

13. An apparatus for the preparation of a curved .composite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises carriages, means for moving said carriages in a cyclic path, spaced support arms mounted on each of the carriages and extending forwardly in the direction of the path of movement, and spaced support arms mounted on each of the carriages and extending rearwardly of the direction of the path of movement, a portion of said forwardly and rearwardly extending support arms of each carriage extending upwardly with a resilient top portion of each support arm during a top portion of the movement in the cyclic path.

14. An apparatus for the preparation of a curved composite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises carriages, means for moving said carriages in a cyclic path including a horizontal top portion of movement, spaced support arms adjustably mounted on each carriage and extending forwardly in the direction of the path of movement, and spaced support arms adjustably mounted on each carriage and extending rearwardly of the direction of the path of movement, a portion of said forwardly and rearwardly extending support arms of each carriage during the horizontal top portion of the movement extending upwardly with a resilient top portion of each support arm, and said adjustable mounting providing variation in the spacing of said forwardly extending support arms and between said rearwardly extending support arms.

15. An apparatus for the preparation of a curved composite assembly including two matched curved glass sheets and a thermoplastic interlayer which comprises carriages, means for moving said carriages in a cyclic path including a horizontal top portion and an inclined portion, spaced support arms mounted on each of the carriages and extending forwardly in the direction of the path of movement, and spaced support arms mounted on each of the carriages and extending rearwardly of the direction of the path of movement, a portion of said forwardly and rearwardly extending support arms of each carriage extending upwardly during the horizontal top portion of the movement in the cyclic path, said rearwardly extending support arms of each carriage having notched surface portions opposing said forwardly extending support arms and said rearwardly extending arms extending below said forwardly extending support arms during movement of the carriage in the inclined portion of the movement in the cyclic path.

References Cited in the tile of this patent UNITED STATES PATENTS 1,794,659 Watkins Mar. 3, 1931 2,046,446 Carlisle July 7, 1936 2,378,016 Hubbard June 12, 1945 2,595,182 Weingarten Apr. 29, 1952 2,612,079 Mahler Sept. 30, 1952 2,682,133 Guilleminot June 29, 1954 2,810,468 Gaeber et al Oct. 22, 1957 n FOREIGN PATENTS 614,616 Germany June 15, 1935 OTHER REFERENCES Kelly: Humidity Conditioning Essential to Safety Glass Manufacture, The Glass Industry (January 1953), pages 22-23 relied upon.

Moser: Glass Bonding, Modern Plastics (February 1954), page 108 relied upon.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No, 2,974,077 March 71 1961 Earl R. Smith et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters PatentI should read as 'corrected below.

Column l, line 49, for "one" read on column lO, line l2,l after "upwardly" insert --e with a resilient top portion of each support arm Signed and sealed this 5th day of December 1961.

` SEAL)l Attest:

ERNEST W. lSWIDEII y DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC 

1. A METHOD FOR THE PREPARATION OF A CURVED COMPOSITE ASSEMBLY WHICH COMPRISES SUPPORTING A CURVED GLASS SHEET WITH ITS CONVEX SURFACE FACING UPWARDLY, PLACING A THERMOPLASTIC SHEET ON THE SUPPORTED SHEET, AND PLACING A MATCHING CURVED GLASS SHEET ON THE UPPER MAJOR SURFACE OF THE THERMOPLASTIC SHEET TO FORM THE COMPOSITE ASSEMBLY,
 8. AN APPARATUS FOR THE PREPARATION OF A CURVED COMPOSITE ASSEMBLY INCLUDING TWO MATCHED CURVED GLASS SHEETS AND A THERMOPLASTIC INTERLAYER WHICH COMPRISES SETS OF MEANS FOR SUPPORTING A CURVED GLASS SHEET WITH ITS ENDS POINTING DOWNWARDLY, EACH SET BEING CONSTRUCTED AND ARRANGED TO SUPPORT ONE OF SAID GLASS SHEETS ONLY BY CONTACT OF THE SET OF SUPPONT MEANS WITH THE LOWER MAJOR SURFACE OF THE GLASS SHEET AT AREAS TRANSVERSELY SPACED APART BETWEEN THE CENTER OF THE GLASS SHEET AND ITS END OF TRANSVERSE SPACING AND LONGITUDINALLY SPACING BETWEEN THE SUPPORT MEANS OF EACH SHEET, AND MEANS FOR CONVEYING THE SETS OF SUPPORT MEANS IN A CYCLIC PATH, SAID CONVEYOR MEANS BEING CONSTRUCTED AND ARRANGED TO PROVIDE SAID SETS OF SUPPORT MEANS IN SPACED RELATIONSHIP AND WITH SAID SUPPORT MEANS OF EACH SET EXTENDING UPWARDLY WITH AN UPPER RESILIENT PORTION FOR EACH SUPPORT MEANS DURING A TOP PORTION OF SAID PATH TO PROVIDE SAID CONTACT OF THE GLASS SHEET BY THE SET OF SUPPORT MEANS. 